const std = @import("std.zig"); const math = std.math; const debug = std.debug; const assert = debug.assert; const testing = std.testing; const mem = std.mem; const builtin = @import("builtin"); const errol = @import("fmt/errol.zig"); const lossyCast = std.math.lossyCast; pub const default_max_depth = 3; /// Renders fmt string with args, calling output with slices of bytes. /// If `output` returns an error, the error is returned from `format` and /// `output` is not called again. pub fn format(context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, comptime fmt: []const u8, args: ...) Errors!void { const State = enum { Start, OpenBrace, CloseBrace, FormatString, Pointer, }; comptime var start_index = 0; comptime var state = State.Start; comptime var next_arg = 0; inline for (fmt) |c, i| { switch (state) { State.Start => switch (c) { '{' => { if (start_index < i) { try output(context, fmt[start_index..i]); } start_index = i; state = State.OpenBrace; }, '}' => { if (start_index < i) { try output(context, fmt[start_index..i]); } state = State.CloseBrace; }, else => {}, }, State.OpenBrace => switch (c) { '{' => { state = State.Start; start_index = i; }, '}' => { try formatType(args[next_arg], fmt[0..0], context, Errors, output, default_max_depth); next_arg += 1; state = State.Start; start_index = i + 1; }, '*' => state = State.Pointer, else => { state = State.FormatString; }, }, State.CloseBrace => switch (c) { '}' => { state = State.Start; start_index = i; }, else => @compileError("Single '}' encountered in format string"), }, State.FormatString => switch (c) { '}' => { const s = start_index + 1; try formatType(args[next_arg], fmt[s..i], context, Errors, output, default_max_depth); next_arg += 1; state = State.Start; start_index = i + 1; }, else => {}, }, State.Pointer => switch (c) { '}' => { try output(context, @typeName(@typeOf(args[next_arg]).Child)); try output(context, "@"); try formatInt(@ptrToInt(args[next_arg]), 16, false, 0, context, Errors, output); next_arg += 1; state = State.Start; start_index = i + 1; }, else => @compileError("Unexpected format character after '*'"), }, } } comptime { if (args.len != next_arg) { @compileError("Unused arguments"); } if (state != State.Start) { @compileError("Incomplete format string: " ++ fmt); } } if (start_index < fmt.len) { try output(context, fmt[start_index..]); } } pub fn formatType( value: var, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, max_depth: usize, ) Errors!void { const T = @typeOf(value); switch (@typeInfo(T)) { builtin.TypeId.ComptimeInt, builtin.TypeId.Int, builtin.TypeId.Float => { return formatValue(value, fmt, context, Errors, output); }, builtin.TypeId.Void => { return output(context, "void"); }, builtin.TypeId.Bool => { return output(context, if (value) "true" else "false"); }, builtin.TypeId.Optional => { if (value) |payload| { return formatType(payload, fmt, context, Errors, output, max_depth); } else { return output(context, "null"); } }, builtin.TypeId.ErrorUnion => { if (value) |payload| { return formatType(payload, fmt, context, Errors, output, max_depth); } else |err| { return formatType(err, fmt, context, Errors, output, max_depth); } }, builtin.TypeId.ErrorSet => { try output(context, "error."); return output(context, @errorName(value)); }, builtin.TypeId.Promise => { return format(context, Errors, output, "promise@{x}", @ptrToInt(value)); }, builtin.TypeId.Enum, builtin.TypeId.Union, builtin.TypeId.Struct => { const has_cust_fmt = comptime cf: { const info = @typeInfo(T); const defs = switch (info) { builtin.TypeId.Struct => |s| s.defs, builtin.TypeId.Union => |u| u.defs, builtin.TypeId.Enum => |e| e.defs, else => unreachable, }; for (defs) |def| { if (mem.eql(u8, def.name, "format")) { break :cf true; } } break :cf false; }; if (has_cust_fmt) return value.format(fmt, context, Errors, output); try output(context, @typeName(T)); switch (comptime @typeId(T)) { builtin.TypeId.Enum => { try output(context, "."); try formatType(@tagName(value), "", context, Errors, output, max_depth); return; }, builtin.TypeId.Struct => { if (max_depth == 0) { return output(context, "{ ... }"); } comptime var field_i = 0; inline while (field_i < @memberCount(T)) : (field_i += 1) { if (field_i == 0) { try output(context, "{ ."); } else { try output(context, ", ."); } try output(context, @memberName(T, field_i)); try output(context, " = "); try formatType(@field(value, @memberName(T, field_i)), "", context, Errors, output, max_depth - 1); } try output(context, " }"); }, builtin.TypeId.Union => { if (max_depth == 0) { return output(context, "{ ... }"); } const info = @typeInfo(T).Union; if (info.tag_type) |UnionTagType| { try output(context, "{ ."); try output(context, @tagName(UnionTagType(value))); try output(context, " = "); inline for (info.fields) |u_field| { if (@enumToInt(UnionTagType(value)) == u_field.enum_field.?.value) { try formatType(@field(value, u_field.name), "", context, Errors, output, max_depth - 1); } } try output(context, " }"); } else { try format(context, Errors, output, "@{x}", @ptrToInt(&value)); } }, else => unreachable, } return; }, builtin.TypeId.Pointer => |ptr_info| switch (ptr_info.size) { builtin.TypeInfo.Pointer.Size.One => switch (@typeInfo(ptr_info.child)) { builtin.TypeId.Array => |info| { if (info.child == u8) { return formatText(value, fmt, context, Errors, output); } return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)); }, builtin.TypeId.Enum, builtin.TypeId.Union, builtin.TypeId.Struct => { return formatType(value.*, fmt, context, Errors, output, max_depth); }, else => return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)), }, builtin.TypeInfo.Pointer.Size.Many => { if (ptr_info.child == u8) { if (fmt.len > 0 and fmt[0] == 's') { const len = mem.len(u8, value); return formatText(value[0..len], fmt, context, Errors, output); } } return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)); }, builtin.TypeInfo.Pointer.Size.Slice => { if (fmt.len > 0 and ((fmt[0] == 'x') or (fmt[0] == 'X'))) { return formatText(value, fmt, context, Errors, output); } const casted_value = ([]const u8)(value); return output(context, casted_value); }, builtin.TypeInfo.Pointer.Size.C => { return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value)); }, }, builtin.TypeId.Array => |info| { if (info.child == u8) { return formatText(value, fmt, context, Errors, output); } return format(context, Errors, output, "{}@{x}", @typeName(T.Child), @ptrToInt(&value)); }, builtin.TypeId.Fn => { return format(context, Errors, output, "{}@{x}", @typeName(T), @ptrToInt(value)); }, else => @compileError("Unable to format type '" ++ @typeName(T) ++ "'"), } } fn formatValue( value: var, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { if (fmt.len > 0) { if (fmt[0] == 'B') { comptime var width: ?usize = null; if (fmt.len > 1) { if (fmt[1] == 'i') { if (fmt.len > 2) width = comptime (parseUnsigned(usize, fmt[2..], 10) catch unreachable); return formatBytes(value, width, 1024, context, Errors, output); } width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable); } return formatBytes(value, width, 1000, context, Errors, output); } } const T = @typeOf(value); switch (@typeId(T)) { builtin.TypeId.Float => return formatFloatValue(value, fmt, context, Errors, output), builtin.TypeId.Int, builtin.TypeId.ComptimeInt => return formatIntValue(value, fmt, context, Errors, output), else => comptime unreachable, } } pub fn formatIntValue( value: var, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { comptime var radix = 10; comptime var uppercase = false; comptime var width = 0; const int_value = if (@typeOf(value) == comptime_int) blk: { const Int = math.IntFittingRange(value, value); break :blk Int(value); } else value; if (fmt.len > 0) { switch (fmt[0]) { 'c' => { if (@typeOf(int_value).bit_count <= 8) { if (fmt.len > 1) @compileError("Unknown format character: " ++ []u8{fmt[1]}); return formatAsciiChar(u8(int_value), context, Errors, output); } }, 'b' => { radix = 2; uppercase = false; width = 0; }, 'd' => { radix = 10; uppercase = false; width = 0; }, 'x' => { radix = 16; uppercase = false; width = 0; }, 'X' => { radix = 16; uppercase = true; width = 0; }, else => @compileError("Unknown format character: " ++ []u8{fmt[0]}), } if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable); } return formatInt(int_value, radix, uppercase, width, context, Errors, output); } fn formatFloatValue( value: var, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { comptime var width: ?usize = null; comptime var float_fmt = 'e'; if (fmt.len > 0) { float_fmt = fmt[0]; if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable); } switch (float_fmt) { 'e' => try formatFloatScientific(value, width, context, Errors, output), '.' => try formatFloatDecimal(value, width, context, Errors, output), else => @compileError("Unknown format character: " ++ []u8{float_fmt}), } } pub fn formatText( bytes: []const u8, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { if (fmt.len > 0) { if (fmt[0] == 's') { comptime var width = 0; if (fmt.len > 1) width = comptime (parseUnsigned(usize, fmt[1..], 10) catch unreachable); return formatBuf(bytes, width, context, Errors, output); } else if ((fmt[0] == 'x') or (fmt[0] == 'X')) { for (bytes) |c| { try formatInt(c, 16, fmt[0] == 'X', 2, context, Errors, output); } return; } else @compileError("Unknown format character: " ++ []u8{fmt[0]}); } return output(context, bytes); } pub fn formatAsciiChar( c: u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { return output(context, (*const [1]u8)(&c)[0..]); } pub fn formatBuf( buf: []const u8, width: usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { try output(context, buf); var leftover_padding = if (width > buf.len) (width - buf.len) else return; const pad_byte: u8 = ' '; while (leftover_padding > 0) : (leftover_padding -= 1) { try output(context, (*const [1]u8)(&pad_byte)[0..1]); } } // Print a float in scientific notation to the specified precision. Null uses full precision. // It should be the case that every full precision, printed value can be re-parsed back to the // same type unambiguously. pub fn formatFloatScientific( value: var, maybe_precision: ?usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { var x = @floatCast(f64, value); // Errol doesn't handle these special cases. if (math.signbit(x)) { try output(context, "-"); x = -x; } if (math.isNan(x)) { return output(context, "nan"); } if (math.isPositiveInf(x)) { return output(context, "inf"); } if (x == 0.0) { try output(context, "0"); if (maybe_precision) |precision| { if (precision != 0) { try output(context, "."); var i: usize = 0; while (i < precision) : (i += 1) { try output(context, "0"); } } } else { try output(context, ".0"); } try output(context, "e+00"); return; } var buffer: [32]u8 = undefined; var float_decimal = errol.errol3(x, buffer[0..]); if (maybe_precision) |precision| { errol.roundToPrecision(&float_decimal, precision, errol.RoundMode.Scientific); try output(context, float_decimal.digits[0..1]); // {e0} case prints no `.` if (precision != 0) { try output(context, "."); var printed: usize = 0; if (float_decimal.digits.len > 1) { const num_digits = math.min(float_decimal.digits.len, precision + 1); try output(context, float_decimal.digits[1..num_digits]); printed += num_digits - 1; } while (printed < precision) : (printed += 1) { try output(context, "0"); } } } else { try output(context, float_decimal.digits[0..1]); try output(context, "."); if (float_decimal.digits.len > 1) { const num_digits = if (@typeOf(value) == f32) math.min(usize(9), float_decimal.digits.len) else float_decimal.digits.len; try output(context, float_decimal.digits[1..num_digits]); } else { try output(context, "0"); } } try output(context, "e"); const exp = float_decimal.exp - 1; if (exp >= 0) { try output(context, "+"); if (exp > -10 and exp < 10) { try output(context, "0"); } try formatInt(exp, 10, false, 0, context, Errors, output); } else { try output(context, "-"); if (exp > -10 and exp < 10) { try output(context, "0"); } try formatInt(-exp, 10, false, 0, context, Errors, output); } } // Print a float of the format x.yyyyy where the number of y is specified by the precision argument. // By default floats are printed at full precision (no rounding). pub fn formatFloatDecimal( value: var, maybe_precision: ?usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { var x = f64(value); // Errol doesn't handle these special cases. if (math.signbit(x)) { try output(context, "-"); x = -x; } if (math.isNan(x)) { return output(context, "nan"); } if (math.isPositiveInf(x)) { return output(context, "inf"); } if (x == 0.0) { try output(context, "0"); if (maybe_precision) |precision| { if (precision != 0) { try output(context, "."); var i: usize = 0; while (i < precision) : (i += 1) { try output(context, "0"); } } else { try output(context, ".0"); } } else { try output(context, "0"); } return; } // non-special case, use errol3 var buffer: [32]u8 = undefined; var float_decimal = errol.errol3(x, buffer[0..]); if (maybe_precision) |precision| { errol.roundToPrecision(&float_decimal, precision, errol.RoundMode.Decimal); // exp < 0 means the leading is always 0 as errol result is normalized. var num_digits_whole = if (float_decimal.exp > 0) @intCast(usize, float_decimal.exp) else 0; // the actual slice into the buffer, we may need to zero-pad between num_digits_whole and this. var num_digits_whole_no_pad = math.min(num_digits_whole, float_decimal.digits.len); if (num_digits_whole > 0) { // We may have to zero pad, for instance 1e4 requires zero padding. try output(context, float_decimal.digits[0..num_digits_whole_no_pad]); var i = num_digits_whole_no_pad; while (i < num_digits_whole) : (i += 1) { try output(context, "0"); } } else { try output(context, "0"); } // {.0} special case doesn't want a trailing '.' if (precision == 0) { return; } try output(context, "."); // Keep track of fractional count printed for case where we pre-pad then post-pad with 0's. var printed: usize = 0; // Zero-fill until we reach significant digits or run out of precision. if (float_decimal.exp <= 0) { const zero_digit_count = @intCast(usize, -float_decimal.exp); const zeros_to_print = math.min(zero_digit_count, precision); var i: usize = 0; while (i < zeros_to_print) : (i += 1) { try output(context, "0"); printed += 1; } if (printed >= precision) { return; } } // Remaining fractional portion, zero-padding if insufficient. assert(precision >= printed); if (num_digits_whole_no_pad + precision - printed < float_decimal.digits.len) { try output(context, float_decimal.digits[num_digits_whole_no_pad .. num_digits_whole_no_pad + precision - printed]); return; } else { try output(context, float_decimal.digits[num_digits_whole_no_pad..]); printed += float_decimal.digits.len - num_digits_whole_no_pad; while (printed < precision) : (printed += 1) { try output(context, "0"); } } } else { // exp < 0 means the leading is always 0 as errol result is normalized. var num_digits_whole = if (float_decimal.exp > 0) @intCast(usize, float_decimal.exp) else 0; // the actual slice into the buffer, we may need to zero-pad between num_digits_whole and this. var num_digits_whole_no_pad = math.min(num_digits_whole, float_decimal.digits.len); if (num_digits_whole > 0) { // We may have to zero pad, for instance 1e4 requires zero padding. try output(context, float_decimal.digits[0..num_digits_whole_no_pad]); var i = num_digits_whole_no_pad; while (i < num_digits_whole) : (i += 1) { try output(context, "0"); } } else { try output(context, "0"); } // Omit `.` if no fractional portion if (float_decimal.exp >= 0 and num_digits_whole_no_pad == float_decimal.digits.len) { return; } try output(context, "."); // Zero-fill until we reach significant digits or run out of precision. if (float_decimal.exp < 0) { const zero_digit_count = @intCast(usize, -float_decimal.exp); var i: usize = 0; while (i < zero_digit_count) : (i += 1) { try output(context, "0"); } } try output(context, float_decimal.digits[num_digits_whole_no_pad..]); } } pub fn formatBytes( value: var, width: ?usize, comptime radix: usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { if (value == 0) { return output(context, "0B"); } const mags_si = " kMGTPEZY"; const mags_iec = " KMGTPEZY"; const magnitude = switch (radix) { 1000 => math.min(math.log2(value) / comptime math.log2(1000), mags_si.len - 1), 1024 => math.min(math.log2(value) / 10, mags_iec.len - 1), else => unreachable, }; const new_value = lossyCast(f64, value) / math.pow(f64, lossyCast(f64, radix), lossyCast(f64, magnitude)); const suffix = switch (radix) { 1000 => mags_si[magnitude], 1024 => mags_iec[magnitude], else => unreachable, }; try formatFloatDecimal(new_value, width, context, Errors, output); if (suffix == ' ') { return output(context, "B"); } const buf = switch (radix) { 1000 => []u8{ suffix, 'B' }, 1024 => []u8{ suffix, 'i', 'B' }, else => unreachable, }; return output(context, buf); } pub fn formatInt( value: var, base: u8, uppercase: bool, width: usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { const int_value = if (@typeOf(value) == comptime_int) blk: { const Int = math.IntFittingRange(value, value); break :blk Int(value); } else value; if (@typeOf(int_value).is_signed) { return formatIntSigned(int_value, base, uppercase, width, context, Errors, output); } else { return formatIntUnsigned(int_value, base, uppercase, width, context, Errors, output); } } fn formatIntSigned( value: var, base: u8, uppercase: bool, width: usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { const uint = @IntType(false, @typeOf(value).bit_count); if (value < 0) { const minus_sign: u8 = '-'; try output(context, (*const [1]u8)(&minus_sign)[0..]); const new_value = @intCast(uint, -(value + 1)) + 1; const new_width = if (width == 0) 0 else (width - 1); return formatIntUnsigned(new_value, base, uppercase, new_width, context, Errors, output); } else if (width == 0) { return formatIntUnsigned(@intCast(uint, value), base, uppercase, width, context, Errors, output); } else { const plus_sign: u8 = '+'; try output(context, (*const [1]u8)(&plus_sign)[0..]); const new_value = @intCast(uint, value); const new_width = if (width == 0) 0 else (width - 1); return formatIntUnsigned(new_value, base, uppercase, new_width, context, Errors, output); } } fn formatIntUnsigned( value: var, base: u8, uppercase: bool, width: usize, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { assert(base >= 2); var buf: [math.max(@typeOf(value).bit_count, 1)]u8 = undefined; const min_int_bits = comptime math.max(@typeOf(value).bit_count, @typeOf(base).bit_count); const MinInt = @IntType(@typeOf(value).is_signed, min_int_bits); var a: MinInt = value; var index: usize = buf.len; while (true) { const digit = a % base; index -= 1; buf[index] = digitToChar(@intCast(u8, digit), uppercase); a /= base; if (a == 0) break; } const digits_buf = buf[index..]; const padding = if (width > digits_buf.len) (width - digits_buf.len) else 0; if (padding > index) { const zero_byte: u8 = '0'; var leftover_padding = padding - index; while (true) { try output(context, (*const [1]u8)(&zero_byte)[0..]); leftover_padding -= 1; if (leftover_padding == 0) break; } mem.set(u8, buf[0..index], '0'); return output(context, buf); } else { const padded_buf = buf[index - padding ..]; mem.set(u8, padded_buf[0..padding], '0'); return output(context, padded_buf); } } pub fn formatIntBuf(out_buf: []u8, value: var, base: u8, uppercase: bool, width: usize) usize { var context = FormatIntBuf{ .out_buf = out_buf, .index = 0, }; formatInt(value, base, uppercase, width, &context, error{}, formatIntCallback) catch unreachable; return context.index; } const FormatIntBuf = struct { out_buf: []u8, index: usize, }; fn formatIntCallback(context: *FormatIntBuf, bytes: []const u8) (error{}!void) { mem.copy(u8, context.out_buf[context.index..], bytes); context.index += bytes.len; } pub fn parseInt(comptime T: type, buf: []const u8, radix: u8) !T { if (!T.is_signed) return parseUnsigned(T, buf, radix); if (buf.len == 0) return T(0); if (buf[0] == '-') { return math.negate(try parseUnsigned(T, buf[1..], radix)); } else if (buf[0] == '+') { return parseUnsigned(T, buf[1..], radix); } else { return parseUnsigned(T, buf, radix); } } test "fmt.parseInt" { testing.expect((parseInt(i32, "-10", 10) catch unreachable) == -10); testing.expect((parseInt(i32, "+10", 10) catch unreachable) == 10); testing.expect(if (parseInt(i32, " 10", 10)) |_| false else |err| err == error.InvalidCharacter); testing.expect(if (parseInt(i32, "10 ", 10)) |_| false else |err| err == error.InvalidCharacter); testing.expect(if (parseInt(u32, "-10", 10)) |_| false else |err| err == error.InvalidCharacter); testing.expect((parseInt(u8, "255", 10) catch unreachable) == 255); testing.expect(if (parseInt(u8, "256", 10)) |_| false else |err| err == error.Overflow); } const ParseUnsignedError = error{ /// The result cannot fit in the type specified Overflow, /// The input had a byte that was not a digit InvalidCharacter, }; pub fn parseUnsigned(comptime T: type, buf: []const u8, radix: u8) ParseUnsignedError!T { var x: T = 0; for (buf) |c| { const digit = try charToDigit(c, radix); if (x != 0) x = try math.mul(T, x, try math.cast(T, radix)); x = try math.add(T, x, try math.cast(T, digit)); } return x; } test "fmt.parseUnsigned" { testing.expect((try parseUnsigned(u16, "050124", 10)) == 50124); testing.expect((try parseUnsigned(u16, "65535", 10)) == 65535); testing.expectError(error.Overflow, parseUnsigned(u16, "65536", 10)); testing.expect((try parseUnsigned(u64, "0ffffffffffffffff", 16)) == 0xffffffffffffffff); testing.expectError(error.Overflow, parseUnsigned(u64, "10000000000000000", 16)); testing.expect((try parseUnsigned(u32, "DeadBeef", 16)) == 0xDEADBEEF); testing.expect((try parseUnsigned(u7, "1", 10)) == 1); testing.expect((try parseUnsigned(u7, "1000", 2)) == 8); testing.expectError(error.InvalidCharacter, parseUnsigned(u32, "f", 10)); testing.expectError(error.InvalidCharacter, parseUnsigned(u8, "109", 8)); testing.expect((try parseUnsigned(u32, "NUMBER", 36)) == 1442151747); // these numbers should fit even though the radix itself doesn't fit in the destination type testing.expect((try parseUnsigned(u1, "0", 10)) == 0); testing.expect((try parseUnsigned(u1, "1", 10)) == 1); testing.expectError(error.Overflow, parseUnsigned(u1, "2", 10)); testing.expect((try parseUnsigned(u1, "001", 16)) == 1); testing.expect((try parseUnsigned(u2, "3", 16)) == 3); testing.expectError(error.Overflow, parseUnsigned(u2, "4", 16)); } pub const parseFloat = @import("fmt/parse_float.zig").parseFloat; test "fmt.parseFloat" { _ = @import("fmt/parse_float.zig"); } pub fn charToDigit(c: u8, radix: u8) (error{InvalidCharacter}!u8) { const value = switch (c) { '0'...'9' => c - '0', 'A'...'Z' => c - 'A' + 10, 'a'...'z' => c - 'a' + 10, else => return error.InvalidCharacter, }; if (value >= radix) return error.InvalidCharacter; return value; } fn digitToChar(digit: u8, uppercase: bool) u8 { return switch (digit) { 0...9 => digit + '0', 10...35 => digit + ((if (uppercase) u8('A') else u8('a')) - 10), else => unreachable, }; } const BufPrintContext = struct { remaining: []u8, }; fn bufPrintWrite(context: *BufPrintContext, bytes: []const u8) !void { if (context.remaining.len < bytes.len) return error.BufferTooSmall; mem.copy(u8, context.remaining, bytes); context.remaining = context.remaining[bytes.len..]; } pub fn bufPrint(buf: []u8, comptime fmt: []const u8, args: ...) ![]u8 { var context = BufPrintContext{ .remaining = buf }; try format(&context, error{BufferTooSmall}, bufPrintWrite, fmt, args); return buf[0 .. buf.len - context.remaining.len]; } pub const AllocPrintError = error{OutOfMemory}; pub fn allocPrint(allocator: *mem.Allocator, comptime fmt: []const u8, args: ...) AllocPrintError![]u8 { var size: usize = 0; format(&size, error{}, countSize, fmt, args) catch |err| switch (err) {}; const buf = try allocator.alloc(u8, size); return bufPrint(buf, fmt, args) catch |err| switch (err) { error.BufferTooSmall => unreachable, // we just counted the size above }; } fn countSize(size: *usize, bytes: []const u8) (error{}!void) { size.* += bytes.len; } test "buf print int" { var buffer: [100]u8 = undefined; const buf = buffer[0..]; testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 2, false, 0), "-101111000110000101001110")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 10, false, 0), "-12345678")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 16, false, 0), "-bc614e")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(-12345678), 16, true, 0), "-BC614E")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, u32(12345678), 10, true, 0), "12345678")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, u32(666), 10, false, 6), "000666")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, u32(0x1234), 16, false, 6), "001234")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, u32(0x1234), 16, false, 1), "1234")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(42), 10, false, 3), "+42")); testing.expect(mem.eql(u8, bufPrintIntToSlice(buf, i32(-42), 10, false, 3), "-42")); } fn bufPrintIntToSlice(buf: []u8, value: var, base: u8, uppercase: bool, width: usize) []u8 { return buf[0..formatIntBuf(buf, value, base, uppercase, width)]; } test "parse u64 digit too big" { _ = parseUnsigned(u64, "123a", 10) catch |err| { if (err == error.InvalidCharacter) return; unreachable; }; unreachable; } test "parse unsigned comptime" { comptime { testing.expect((try parseUnsigned(usize, "2", 10)) == 2); } } test "fmt.format" { { const value: ?i32 = 1234; try testFmt("optional: 1234\n", "optional: {}\n", value); } { const value: ?i32 = null; try testFmt("optional: null\n", "optional: {}\n", value); } { const value: anyerror!i32 = 1234; try testFmt("error union: 1234\n", "error union: {}\n", value); } { const value: anyerror!i32 = error.InvalidChar; try testFmt("error union: error.InvalidChar\n", "error union: {}\n", value); } { const value: u3 = 0b101; try testFmt("u3: 5\n", "u3: {}\n", value); } { const value: u8 = 'a'; try testFmt("u8: a\n", "u8: {c}\n", value); } { const value: u8 = 0b1100; try testFmt("u8: 0b1100\n", "u8: 0b{b}\n", value); } { var buf1: [32]u8 = undefined; var context = BufPrintContext{ .remaining = buf1[0..] }; try formatType(1234, "", &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth); var res = buf1[0 .. buf1.len - context.remaining.len]; testing.expect(mem.eql(u8, res, "1234")); context = BufPrintContext{ .remaining = buf1[0..] }; try formatType('a', "c", &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth); res = buf1[0 .. buf1.len - context.remaining.len]; testing.expect(mem.eql(u8, res, "a")); context = BufPrintContext{ .remaining = buf1[0..] }; try formatType(0b1100, "b", &context, error{BufferTooSmall}, bufPrintWrite, default_max_depth); res = buf1[0 .. buf1.len - context.remaining.len]; testing.expect(mem.eql(u8, res, "1100")); } { const value: [3]u8 = "abc"; try testFmt("array: abc\n", "array: {}\n", value); try testFmt("array: abc\n", "array: {}\n", &value); var buf: [100]u8 = undefined; try testFmt( try bufPrint(buf[0..], "array: [3]u8@{x}\n", @ptrToInt(&value)), "array: {*}\n", &value, ); } { const value: []const u8 = "abc"; try testFmt("slice: abc\n", "slice: {}\n", value); } { const value = @intToPtr(*i32, 0xdeadbeef); try testFmt("pointer: i32@deadbeef\n", "pointer: {}\n", value); try testFmt("pointer: i32@deadbeef\n", "pointer: {*}\n", value); } { const value = @intToPtr(fn () void, 0xdeadbeef); try testFmt("pointer: fn() void@deadbeef\n", "pointer: {}\n", value); } { const value = @intToPtr(fn () void, 0xdeadbeef); try testFmt("pointer: fn() void@deadbeef\n", "pointer: {}\n", value); } try testFmt("buf: Test \n", "buf: {s5}\n", "Test"); try testFmt("buf: Test\n Other text", "buf: {s}\n Other text", "Test"); try testFmt("cstr: Test C\n", "cstr: {s}\n", c"Test C"); try testFmt("cstr: Test C \n", "cstr: {s10}\n", c"Test C"); try testFmt("file size: 63MiB\n", "file size: {Bi}\n", usize(63 * 1024 * 1024)); try testFmt("file size: 66.06MB\n", "file size: {B2}\n", usize(63 * 1024 * 1024)); { const Struct = struct { field: u8, }; const value = Struct{ .field = 42 }; try testFmt("struct: Struct{ .field = 42 }\n", "struct: {}\n", value); try testFmt("struct: Struct{ .field = 42 }\n", "struct: {}\n", &value); } { const Struct = struct { a: u0, b: u1, }; const value = Struct{ .a = 0, .b = 1 }; try testFmt("struct: Struct{ .a = 0, .b = 1 }\n", "struct: {}\n", value); } { const Enum = enum { One, Two, }; const value = Enum.Two; try testFmt("enum: Enum.Two\n", "enum: {}\n", value); try testFmt("enum: Enum.Two\n", "enum: {}\n", &value); } { var buf1: [32]u8 = undefined; const value: f32 = 1.34; const result = try bufPrint(buf1[0..], "f32: {e}\n", value); testing.expect(mem.eql(u8, result, "f32: 1.34000003e+00\n")); } { var buf1: [32]u8 = undefined; const value: f32 = 12.34; const result = try bufPrint(buf1[0..], "f32: {e}\n", value); testing.expect(mem.eql(u8, result, "f32: 1.23400001e+01\n")); } { var buf1: [32]u8 = undefined; const value: f64 = -12.34e10; const result = try bufPrint(buf1[0..], "f64: {e}\n", value); testing.expect(mem.eql(u8, result, "f64: -1.234e+11\n")); } { // This fails on release due to a minor rounding difference. // --release-fast outputs 9.999960000000001e-40 vs. the expected. // TODO fix this, it should be the same in Debug and ReleaseFast if (builtin.mode == builtin.Mode.Debug) { var buf1: [32]u8 = undefined; const value: f64 = 9.999960e-40; const result = try bufPrint(buf1[0..], "f64: {e}\n", value); testing.expect(mem.eql(u8, result, "f64: 9.99996e-40\n")); } } { var buf1: [32]u8 = undefined; const value: f64 = 1.409706e-42; const result = try bufPrint(buf1[0..], "f64: {e5}\n", value); testing.expect(mem.eql(u8, result, "f64: 1.40971e-42\n")); } { var buf1: [32]u8 = undefined; const value: f64 = @bitCast(f32, u32(814313563)); const result = try bufPrint(buf1[0..], "f64: {e5}\n", value); testing.expect(mem.eql(u8, result, "f64: 1.00000e-09\n")); } { var buf1: [32]u8 = undefined; const value: f64 = @bitCast(f32, u32(1006632960)); const result = try bufPrint(buf1[0..], "f64: {e5}\n", value); testing.expect(mem.eql(u8, result, "f64: 7.81250e-03\n")); } { // libc rounds 1.000005e+05 to 1.00000e+05 but zig does 1.00001e+05. // In fact, libc doesn't round a lot of 5 cases up when one past the precision point. var buf1: [32]u8 = undefined; const value: f64 = @bitCast(f32, u32(1203982400)); const result = try bufPrint(buf1[0..], "f64: {e5}\n", value); testing.expect(mem.eql(u8, result, "f64: 1.00001e+05\n")); } { var buf1: [32]u8 = undefined; const result = try bufPrint(buf1[0..], "f64: {}\n", math.nan_f64); testing.expect(mem.eql(u8, result, "f64: nan\n")); } if (builtin.arch != builtin.Arch.arm) { // negative nan is not defined by IEE 754, // and ARM thus normalizes it to positive nan var buf1: [32]u8 = undefined; const result = try bufPrint(buf1[0..], "f64: {}\n", -math.nan_f64); testing.expect(mem.eql(u8, result, "f64: -nan\n")); } { var buf1: [32]u8 = undefined; const result = try bufPrint(buf1[0..], "f64: {}\n", math.inf_f64); testing.expect(mem.eql(u8, result, "f64: inf\n")); } { var buf1: [32]u8 = undefined; const result = try bufPrint(buf1[0..], "f64: {}\n", -math.inf_f64); testing.expect(mem.eql(u8, result, "f64: -inf\n")); } { var buf1: [64]u8 = undefined; const value: f64 = 1.52314e+29; const result = try bufPrint(buf1[0..], "f64: {.}\n", value); testing.expect(mem.eql(u8, result, "f64: 152314000000000000000000000000\n")); } { var buf1: [32]u8 = undefined; const value: f32 = 1.1234; const result = try bufPrint(buf1[0..], "f32: {.1}\n", value); testing.expect(mem.eql(u8, result, "f32: 1.1\n")); } { var buf1: [32]u8 = undefined; const value: f32 = 1234.567; const result = try bufPrint(buf1[0..], "f32: {.2}\n", value); testing.expect(mem.eql(u8, result, "f32: 1234.57\n")); } { var buf1: [32]u8 = undefined; const value: f32 = -11.1234; const result = try bufPrint(buf1[0..], "f32: {.4}\n", value); // -11.1234 is converted to f64 -11.12339... internally (errol3() function takes f64). // -11.12339... is rounded back up to -11.1234 testing.expect(mem.eql(u8, result, "f32: -11.1234\n")); } { var buf1: [32]u8 = undefined; const value: f32 = 91.12345; const result = try bufPrint(buf1[0..], "f32: {.5}\n", value); testing.expect(mem.eql(u8, result, "f32: 91.12345\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 91.12345678901235; const result = try bufPrint(buf1[0..], "f64: {.10}\n", value); testing.expect(mem.eql(u8, result, "f64: 91.1234567890\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 0.0; const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 5.700; const result = try bufPrint(buf1[0..], "f64: {.0}\n", value); testing.expect(mem.eql(u8, result, "f64: 6\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 9.999; const result = try bufPrint(buf1[0..], "f64: {.1}\n", value); testing.expect(mem.eql(u8, result, "f64: 10.0\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 1.0; const result = try bufPrint(buf1[0..], "f64: {.3}\n", value); testing.expect(mem.eql(u8, result, "f64: 1.000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 0.0003; const result = try bufPrint(buf1[0..], "f64: {.8}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00030000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 1.40130e-45; const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = 9.999960e-40; const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00000\n")); } // libc checks { var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(916964781))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00001\n")); } { var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(925353389))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.00001\n")); } { var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(1036831278))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.10000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(1065353133))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 1.00000\n")); } { var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(1092616192))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 10.00000\n")); } // libc differences { var buf1: [32]u8 = undefined; // This is 0.015625 exactly according to gdb. We thus round down, // however glibc rounds up for some reason. This occurs for all // floats of the form x.yyyy25 on a precision point. const value: f64 = f64(@bitCast(f32, u32(1015021568))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 0.01563\n")); } // std-windows-x86_64-Debug-bare test case fails { // errol3 rounds to ... 630 but libc rounds to ...632. Grisu3 // also rounds to 630 so I'm inclined to believe libc is not // optimal here. var buf1: [32]u8 = undefined; const value: f64 = f64(@bitCast(f32, u32(1518338049))); const result = try bufPrint(buf1[0..], "f64: {.5}\n", value); testing.expect(mem.eql(u8, result, "f64: 18014400656965630.00000\n")); } //custom type format { const Vec2 = struct { const SelfType = @This(); x: f32, y: f32, pub fn format( self: SelfType, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { switch (fmt.len) { 0 => return std.fmt.format(context, Errors, output, "({.3},{.3})", self.x, self.y), 1 => switch (fmt[0]) { //point format 'p' => return std.fmt.format(context, Errors, output, "({.3},{.3})", self.x, self.y), //dimension format 'd' => return std.fmt.format(context, Errors, output, "{.3}x{.3}", self.x, self.y), else => unreachable, }, else => unreachable, } } }; var buf1: [32]u8 = undefined; var value = Vec2{ .x = 10.2, .y = 2.22, }; try testFmt("point: (10.200,2.220)\n", "point: {}\n", &value); try testFmt("dim: 10.200x2.220\n", "dim: {d}\n", &value); // same thing but not passing a pointer try testFmt("point: (10.200,2.220)\n", "point: {}\n", value); try testFmt("dim: 10.200x2.220\n", "dim: {d}\n", value); } //struct format { const S = struct { a: u32, b: anyerror, }; const inst = S{ .a = 456, .b = error.Unused, }; try testFmt("S{ .a = 456, .b = error.Unused }", "{}", inst); } //union format { const TU = union(enum) { float: f32, int: u32, }; const UU = union { float: f32, int: u32, }; const EU = extern union { float: f32, int: u32, }; const tu_inst = TU{ .int = 123 }; const uu_inst = UU{ .int = 456 }; const eu_inst = EU{ .float = 321.123 }; try testFmt("TU{ .int = 123 }", "{}", tu_inst); var buf: [100]u8 = undefined; const uu_result = try bufPrint(buf[0..], "{}", uu_inst); testing.expect(mem.eql(u8, uu_result[0..3], "UU@")); const eu_result = try bufPrint(buf[0..], "{}", eu_inst); testing.expect(mem.eql(u8, uu_result[0..3], "EU@")); } //enum format { const E = enum { One, Two, Three, }; const inst = E.Two; try testFmt("E.Two", "{}", inst); } //self-referential struct format { const S = struct { const SelfType = @This(); a: ?*SelfType, }; var inst = S{ .a = null, }; inst.a = &inst; try testFmt("S{ .a = S{ .a = S{ .a = S{ ... } } } }", "{}", inst); } //print bytes as hex { const some_bytes = "\xCA\xFE\xBA\xBE"; try testFmt("lowercase: cafebabe\n", "lowercase: {x}\n", some_bytes); try testFmt("uppercase: CAFEBABE\n", "uppercase: {X}\n", some_bytes); //Test Slices try testFmt("uppercase: CAFE\n", "uppercase: {X}\n", some_bytes[0..2]); try testFmt("lowercase: babe\n", "lowercase: {x}\n", some_bytes[2..]); const bytes_with_zeros = "\x00\x0E\xBA\xBE"; try testFmt("lowercase: 000ebabe\n", "lowercase: {x}\n", bytes_with_zeros); } } fn testFmt(expected: []const u8, comptime template: []const u8, args: ...) !void { var buf: [100]u8 = undefined; const result = try bufPrint(buf[0..], template, args); if (mem.eql(u8, result, expected)) return; std.debug.warn("\n====== expected this output: =========\n"); std.debug.warn("{}", expected); std.debug.warn("\n======== instead found this: =========\n"); std.debug.warn("{}", result); std.debug.warn("\n======================================\n"); return error.TestFailed; } pub fn trim(buf: []const u8) []const u8 { var start: usize = 0; while (start < buf.len and isWhiteSpace(buf[start])) : (start += 1) {} var end: usize = buf.len; while (true) { if (end > start) { const new_end = end - 1; if (isWhiteSpace(buf[new_end])) { end = new_end; continue; } } break; } return buf[start..end]; } test "fmt.trim" { testing.expect(mem.eql(u8, "abc", trim("\n abc \t"))); testing.expect(mem.eql(u8, "", trim(" "))); testing.expect(mem.eql(u8, "", trim(""))); testing.expect(mem.eql(u8, "abc", trim(" abc"))); testing.expect(mem.eql(u8, "abc", trim("abc "))); } pub fn isWhiteSpace(byte: u8) bool { return switch (byte) { ' ', '\t', '\n', '\r' => true, else => false, }; } pub fn hexToBytes(out: []u8, input: []const u8) !void { if (out.len * 2 < input.len) return error.InvalidLength; var in_i: usize = 0; while (in_i != input.len) : (in_i += 2) { const hi = try charToDigit(input[in_i], 16); const lo = try charToDigit(input[in_i + 1], 16); out[in_i / 2] = (hi << 4) | lo; } } test "fmt.hexToBytes" { const test_hex_str = "909A312BB12ED1F819B3521AC4C1E896F2160507FFC1C8381E3B07BB16BD1706"; var pb: [32]u8 = undefined; try hexToBytes(pb[0..], test_hex_str); try testFmt(test_hex_str, "{X}", pb); } test "fmt.formatIntValue with comptime_int" { const value: comptime_int = 123456789123456789; var buf = try std.Buffer.init(std.debug.global_allocator, ""); try formatIntValue(value, "", &buf, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append); assert(mem.eql(u8, buf.toSlice(), "123456789123456789")); } test "fmt.formatType max_depth" { const Vec2 = struct { const SelfType = @This(); x: f32, y: f32, pub fn format( self: SelfType, comptime fmt: []const u8, context: var, comptime Errors: type, output: fn (@typeOf(context), []const u8) Errors!void, ) Errors!void { return std.fmt.format(context, Errors, output, "({.3},{.3})", self.x, self.y); } }; const E = enum { One, Two, Three, }; const TU = union(enum) { const SelfType = @This(); float: f32, int: u32, ptr: ?*SelfType, }; const S = struct { const SelfType = @This(); a: ?*SelfType, tu: TU, e: E, vec: Vec2, }; var inst = S{ .a = null, .tu = TU{ .ptr = null }, .e = E.Two, .vec = Vec2{ .x = 10.2, .y = 2.22 }, }; inst.a = &inst; inst.tu.ptr = &inst.tu; var buf0 = try std.Buffer.init(std.debug.global_allocator, ""); try formatType(inst, "", &buf0, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 0); assert(mem.eql(u8, buf0.toSlice(), "S{ ... }")); var buf1 = try std.Buffer.init(std.debug.global_allocator, ""); try formatType(inst, "", &buf1, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 1); assert(mem.eql(u8, buf1.toSlice(), "S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }")); var buf2 = try std.Buffer.init(std.debug.global_allocator, ""); try formatType(inst, "", &buf2, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 2); assert(mem.eql(u8, buf2.toSlice(), "S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }")); var buf3 = try std.Buffer.init(std.debug.global_allocator, ""); try formatType(inst, "", &buf3, @typeOf(std.Buffer.append).ReturnType.ErrorSet, std.Buffer.append, 3); assert(mem.eql(u8, buf3.toSlice(), "S{ .a = S{ .a = S{ .a = S{ ... }, .tu = TU{ ... }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ ... } }, .e = E.Two, .vec = (10.200,2.220) }, .tu = TU{ .ptr = TU{ .ptr = TU{ ... } } }, .e = E.Two, .vec = (10.200,2.220) }")); }